Amiodarone and risk of liver cirrhosis: a nationwide, population-based study

The Safety Profile of Amiodarone Among Older Adults (Age ≥75 Years): A Pharmacovigilance Study from the FDA Data

BACKGROUND

Amiodarone is a widely used antiarrhythmic agent with significant toxicities and drug interactions more likely to affect older adults. Nevertheless, data regarding amiodarone safety in this population are limited.

METHODS

We conducted a retrospective analysis of FDA [Food and Drug Administration] Adverse Event Reporting System (FAERS) data from 2003 to 2024. Reports with amiodarone as the primary suspect were compared with other antiarrhythmics (sotalol, dronedarone, flecainide, propafenone, dofetilide). Disproportionality analysis assessed reporting odds ratios (RORs) for predefined adverse events in adults (<75 years) and older adults (≥75 years). Interaction analysis evaluated differences between age groups.

RESULTS

Among 9196 amiodarone FAERS reports, 4129 (44.9%) involved older adults. Hyperthyroidism (ROR 39.1; 95% confidence interval [CI], 25-61 and ROR 23.4; 95% CI, 11-49.8) and hypothyroidism (ROR 36.9; 95% CI, 15.2-89.8 and ROR 24.5; 95% CI, 11.5-52.1) were substantially over-reported in amiodarone users among both adults and older adults, respectively. Drug-induced liver injury and peripheral neuropathy were also over-reported without a significant age interaction. Interstitial lung disease was reported more frequently in amiodarone users overall, with significantly higher reporting in older adults (ROR 11.4; 95% CI, 6.9-18.6 vs 4.9; 95% CI, 3.4-7.0; Pinteraction = .007). Bradycardia was also over-reported in older adults compared with adults (ROR 1.6; 95% CI, 1.3-2 vs 1.0; 95% CI, 0.8-1.3; Pinteraction = .003). Torsades de pointes/QT prolongation were less frequently reported in both age groups.

CONCLUSIONS

In this global postmarketing study, interstitial lung disease and bradycardia were more frequently reported in older adults treated with amiodarone. These findings support vigilant monitoring for these adverse events, particularly in older patients.

Natural Products in Liver Fibrosis Management: A Five-year Review

Liver fibrosis, characterized by the overproduction of extracellular matrix proteins within liver tissue, poses a rising global health concern. However, no approved antifibrotic drugs are currently available, highlighting the critical need for understanding the molecular mechanisms of liver fibrosis. This knowledge could not only aid in developing therapies but also enable early intervention, enhance disease prediction, and improve our understanding of the interaction between various underlying conditions and the liver. Notably, natural products used in traditional medicine systems worldwide and demonstrating diverse biochemical and pharmacological activities are increasingly recognized for their potential in treating liver fibrosis. This review aims to comprehensively understand liver fibrosis, emphasizing the molecular mechanisms and advancements in exploring natural products' antifibrotic potential over the past five years. It also acknowledges the challenges in their development and seeks to underscore their potency in enhancing patient prognosis and reducing the global burden of liver disease.

Impact of amiodarone use on metoprolol concentrations, α-OH-metoprolol concentrations, metoprolol dosing and heart rate: A cross-sectional study

Small studies suggest that amiodarone is a weak inhibitor of cytochrome P450 (CYP) 2D6. Inhibition of CYP2D6 leads to increases in concentrations of drugs metabolized by the enzyme, such as metoprolol. Considering that both metoprolol and amiodarone have β-adrenergic blocking properties and that the modest interaction between the two drugs would result in increased metoprolol concentrations, this could lead to a higher risk of bradycardia and atrioventricular block. The primary objective of this study was to evaluate whether metoprolol plasma concentrations collected at random timepoints from patients enrolled in the Montreal Heart Institute Hospital Cohort could be useful in identifying the modest pharmacokinetic interaction between amiodarone and metoprolol. We performed an analysis of a cross-sectional study, conducted as part of the Montreal Heart Institute Hospital Cohort. All participants were self-described "White" adults with metoprolol being a part of their daily pharmacotherapy regimen. Of the 999 patients being treated with metoprolol, 36 were also taking amiodarone. Amiodarone use was associated with higher metoprolol concentrations following adjustment for different covariates (p = .0132). Consistently, the association between amiodarone use and lower heart rate was apparent and significant after adjustment for all covariates under study (p = .0001). Our results highlight that single randomly collected blood samples can be leveraged to detect modest pharmacokinetic interactions.

Chronic Oral Amiodarone as a Cause of Acute Liver Failure

Acute liver failure (ALF) is a rare condition that can have a variable clinical course and potentially fatal outcomes. Medication toxicity is a known etiology, however liver failure induced by amiodarone is rare and has been reported mostly in the setting of intravenous (IV) infusion. We present an 84-year-old patient who developed ALF after chronic use of oral amiodarone. The patient received supportive care and her symptoms improved.

CLInical Profile and Side Effects of chronic use of oral Amiodarone in cardiology outpatients department (CLIPSE-A Study)- A prospective observational study

Background

Amiodarone belongs to Class-III anti-arrhythmic drugs. It is one of the most effective anti-arrhythmic drugs used to treat or prevent several types of arrhythmias including atrial fibrillation, atrial flutter, ventricular tachycardia, and wide complex tachycardia, but unfortunately carries a high toxicity profile. Also, side effects of amiodarone involving various organs can be life-threatening.

Materials & methods

This was an observational study carried out for six months i.e from April to September. The study included patients who are on amiodarone for greater than or equal to six months. The required data was collected in-person from the case sheets, treatment charts, and by interviewing the patients. The data for 67 patients was documented in suitable data collection form for analysis.

Results

From our study data, it was noted that amiodarone was used for 3 different indications-atrial fibrillation, atrial flutter, and ventricular tachycardia. Among 67 patients enrolled, 38 had no side-effects. Side-effects data in the rest grouped basing on the organ system affected: 9 patients had renal effects, 6 patients had ophthalmic effects, 4 patients had endocrine effects, and 5 patients had hepatic effects.

Conclusion

From our study, it is concluded that amiodarone is a safe and effective anti-arrhythmic drug at lower doses i.e. 200-1100 mg/week. When treated in lower doses of 1400–2800 mg/week, many side effects have been incident. Although these effects are mild and develop only after prolonged usage of the drug, it should be used judiciously.

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Amiodarone has an unusual spectrum of side effects with a prevalence of 15% in the first year, increasing up to 50% during long-term use.

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Our study demonstrated amiodarone does not produce significant side-effects when used in doses of 200–1100 mg/week.

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Few side-effects are observed when amiodarone is used in higher doses of 1200–2800 mg/week.

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When a side-effect is observed, mere reducing the dose or withdrawal of drug might help.

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In most of the cases of atrial fibrillation, amiodarone is discontinued or altered in first year of treatment basing on risk/benefit ratio.

Dose-dependent interaction of two heavy metals with amiodarone toxicity in Saccharomyces cerevisiae

Amiodarone (AMD) is an antiarrhythmic drug that induces idiosyncratic toxicity. Environmental pollutants, including heavy metals, could interact with its toxicity by affecting pharmacokinetics and pharmacodynamics. Other levels of interaction could exist in yeast, such as oxidative stress and the general stress response. In this study, we investigated the interaction of mercury chloride (HgCl₂) and cadmium chloride (CdCl₂) with AMD toxicity on Saccharomyces cerevisiae. Interaction type - synergistic, additive, or antagonistic - was determined by median drug effect analysis using "CompuSyn". HgCl₂ potentiated AMD toxicity at high doses (≥ 71.4 μm, which yielded more than 60% inhibition). CdCl₂ acted similarly at high doses (≥ 57.9 μm). An antagonistic effect appeared at lower doses with both heavy metals (≤ 49.4 μm for HgCl₂ and AMD; ≤ 18.9 μm for CdCl₂ and AMD). The threshold concentrations (HgCl₂ or CdCl₂ combined with AMD) that switched the interaction from antagonistic to additive, and then to synergistic, were decreased in the yeast strain mutant in catalase (CTT1), suggesting an important role for this enzyme. Moreover, mutation of the nutrient sensing receptor gene GPR1 caused the synergistic interaction of CdCl₂, but not HgCl₂, with AMD to occur at the lowest tested concentrations (1.2 μm). The reverse was obtained with the mutant strain in calcium-manganese transporter gene PMR1, where the synergistic interaction of HgCl₂ with AMD occurred at concentrations (20.7 μm) lower than that of the wild type (71.4 μm). These results demonstrated a dose-dependent interaction between the two heavy metals with AMD toxicity, and the involvement of oxidative stress, calcium homeostasis, and nutrient sensing in the observed interaction.

Association between cirrhosis and herpes zoster in a cohort study in Taiwan

OBJECTIVES

The aim of the study was to assess if an association exists between cirrhosis and herpes zoster in Taiwan.

METHODS

A retrospective cohort study was designed to analyse the 2000-2013 claim dataset of 1 million insured residents who were randomly sampled from the Taiwan National Health Insurance Program. In total, 16 190 subjects aged 20-84 years old with newly diagnosed cirrhosis since 2000 to 2012 were identified as the cirrhosis group and 16 190 sex- and age-matched subjects without cirrhosis were selected as the non-cirrhosis group. Both cirrhosis and non-cirrhosis groups were followed until a new diagnosis of herpes zoster was made or until the end of 2013. The multivariable Cox proportional hazard regression model was applied to calculate the hazard ratio (HR) and 95% confidence interval (CI) for herpes zoster associated with cirrhosis.

RESULTS

The incidence rate of herpes zoster was 1.08-fold greater in the cirrhosis group than the non-cirrhosis group (8.33 vs 7.69 per 1000 person-years, 95%CI 1.02-1.15). After adjusting for confounders, the adjusted HR of herpes zoster was 1.11 (95% CI 1.004-1.24) for the cirrhosis group compared with the non-cirrhosis group. The adjusted HR increased to 1.33 (95% CI 1.02-1.74) for the decompensated cirrhosis group compared with the non-cirrhosis group.

CONCLUSIONS

Cirrhosis is associated with a small but significant increase in the risk of herpes zoster. Given that the risk of herpes zoster is small and the expense of herpes zoster vaccination is high, whether cirrhotic persons need to be vaccinated should assess the balance of cost and benefit.

Drug-induced Fatty Liver Disease: Pathogenesis and Treatment

Metabolic dysfunction-associated fatty liver disease (commonly known as MAFLD) impacts global health in epidemic proportions, and the resulting morbidity, mortality and economic burden is enormous. While much attention has been given to metabolic syndrome and obesity as offending factors, a growing incidence of polypharmacy, especially in the elderly, has greatly increased the risk of drug-induced liver injury (DILI) in general, and drug-induced fatty liver disease (DIFLD) in particular. This review focuses on the contribution of DIFLD to DILI in terms of epidemiology, pathophysiology, the most common drugs associated with DIFLD, and treatment strategies.

Role of amiodarone in the management of atrial arrhythmias in adult Fontan patients

BACKGROUND

Patients with Fontan circulation are known to be at high risk for developing atrial tachyarrhythmias (AAs). Our objective was to examine the efficacy and safety of amiodarone in the management of ATs in adult Fontan patients.

METHODS

Primary outcomes of this single-centre, retrospective study included freedom from AAs and incidence of adverse effects of amiodarone on Fontan patients. Heart failure (HF) events and composite outcomes of death from any cause, Fontan revision and heart transplantation were evaluated as secondary outcomes. Predictors of HF and discontinuing amiodarone were also evaluated.

RESULTS

A total of 61 patients (mean age 31.6±11.3 years, 40.9% female), who were treated with amiodarone in between 1995 and 2018, were included. AAs free survival at 1, 3 and 5 years were 76.2%, 56.9% and 30.6%, respectively. During a median follow-up of 50.5 months, 34 (55.7%) patients developed side effects, and 20 (32.8%) patients discontinued amiodarone due to side effects. Thyroid dysfunction was the most common side effect (n=26, 76.5%), amiodarone-induced thyrotoxicosis (AIT) (n=16, 27.1%) being most common thyroid dysfunction. Young age (age <28.5 years) was associated with discontinuing amiodarone (HR 5.50, 95% CI 1.19 to 25.4, p=0.029). AIT significantly increased risk of HF (HR 4.82, 95% CI 1.71 to 13.6, p=0.003).

CONCLUSIONS

Short-term efficacy of amiodarone in Fontan physiology is acceptable. However, long-term administration is associated with a reduction of efficacy and a significant prevalence of non-cardiac side effects. AIT is associated with exacerbation of HF. The judicious use of amiodarone administration should be considered in this population.